Severe endocrine and nonendocrine manifestations of the McCune-Albright syndrome associated with activating mutations of stimulatory G protein GS

Fibrous Dysplasia Polyostotic: When Radiology Clarifies the Diagnosis

Fibrous dysplasia is a rare non-hereditary congenital condition characterized by 2 main forms: monostotic and polyostotic. Monostotic is the more common form, while polyostotic, often associated with a syndrome, is rarer. The case presented involves a 10-year-old patient who was diagnosed with polyostotic fibrous dysplasia accompanied by an endocrinopathy. This report explores the clinical and radiological aspects of this condition based on the patient's case.

Genetic characterization of intramuscular myxomas

Introduction: Intramuscular myxomas are benign tumors that are challenging to diagnose, especially on core needle biopsies. Acquired chromosomal aberrations and pathogenic variants in codon 201 or codon 227 in GNAS complex locus gene (GNAS) have been reported in these tumors. Here we present our genetic findings in a series of 22 intramuscular myxomas. Materials and methods: The tumors were investigated for the presence of acquired chromosomal aberrations using G-banding and karyotyping. Pathogenic variants in codon 201 or codon 227 of GNAS were assessed using direct cycle Sanger sequencing and Ion AmpliSeq Cancer Hotspot Panel v2 methodologies. Results: Eleven tumors carried chromosomal abnormalities. Six tumors had numerical, four had structural, and one had both numerical and structural chromosomal aberrations. Gains of chromosomes 7 and 8 were the most common abnormalities being found in five and four tumors respectively. Pathogenic variants in GNAS were detected in 19 myxomas (86%) with both methodologies. The detected pathogenic variants were p.R201H in nine cases (seven with abnormal and two with normal karyotypes), p.R201C in five cases, all with normal karyotypes, p.R201S in three cases (two with abnormal and one with normal karyotype), p.R201G in one case with a normal karyotype, and p.Q227E in one case with a normal karyotype. Conclusion: Firstly, our data indicate a possible association between chromosomal abnormalities and GNAS pathogenic variants in intramuscular myxomas. Secondly, the presence of the rare pathogenic variants R201S, p.R201G and p.Q227E in 26% (5 out of 19) of myxomas with GNAS pathogenic variants shows that methodologies designed to detect only the common "hotspot" of p.R201C and p.R201H will give false negative results. Finally, a comparison between Ion AmpliSeq Cancer Hotspot Panel v2 and direct cycle Sanger sequencing showed that direct cycle Sanger sequencing provides a quick, reliable, and relatively cheap method to detect GNAS pathogenic variants, matching even the most cutting-edge sequencing methods.

Neonatal cholestasis as the onset symptom of McCune-Albright syndrome: case reports and a literature review

Aim

This study aimed to summarize and show the characteristics and evolutionary process of neonatal cholestasis caused by McCune-Albright syndrome (MAS), as neonatal cholestasis may be the initial manifestation of MAS before other classic clinical features appear.

Methods

The clinical characteristics, treatment methods, and outcomes of three neonatal cholestasis cases caused by MAS in our center were retrospectively studied. In addition, all the reported cases of MAS combined with cholestasis were reviewed and summarized to show the cholestatic features in them.

Results

We have confirmed three MAS cases in our center, presenting onset symptoms of jaundice, pale stool, and neonatal cholestasis soon after birth. The cholestasis subsided spontaneously at around the sixth month. The literature review showed that the levels of total bilirubin, conjugated bilirubin, ALT, AST, and GGT in neonatal MAS cholestasis cases were 207 μmol/L (range 65-445 μmol/L), 162 μmol/L (range 46-412 μmol/L), 821 U/L (range 85-3,597 U/L), 532 U/L (range 127-3,633 U/L), and 244 U/L (range 79-3,800 U/L), respectively. Liver histology showed canalicular and hepatocellular cholestasis, giant hepatic cell transformation, and bile paucity. Extrahepatic manifestations such as café-au-lait pigmented skin lesions, Cushing's syndrome, hyperthyroidism, renal tubular dysfunction, and skeletal abnormalities could occur simultaneously when jaundice occurred. GNAS mutations had a high positive rate (83.3%-100%) in liver tissue with cholestasis. Neonatal cholestasis caused by MAS could be self-resolved, but hepatic lesions persist and have malignant potential.

Conclusion

MAS can be one of the causes of neonatal cholestasis, which may be the first manifestation of the disease. Extrahepatic coexisting symptoms of MAS and liver histology can help to distinguish MAS from other etiology of cholestasis. Detecting GNAS mutations in liver tissue may shorten diagnostic time and is of particular interest in the partial and atypical forms of MAS with neonatal cholestasis. Neonatal cholestasis in children with MAS can self-resolve, but liver dysfunction and malignant lesions persist.

Case Report: Severe McCune-Albright syndrome presenting with neonatal Cushing syndrome: navigating through clinical obstacles

Background

Café-au-lait skin macules, Cushing syndrome (CS), hyperthyroidism, and liver and cardiac dysfunction are presenting features of neonatal McCune-Albright syndrome (MAS), CS being the rarest endocrine feature. Although spontaneous resolution of hypercortisolism has been reported, outcome is usually unfavorable. While a unified approach to diagnosis, treatment, and follow-up is lacking, herein successful treatment and long-term follow-up of a rare case is presented.

Clinical case

An 11-day-old girl born small for gestational age presented with deterioration of well-being and weight loss. Large hyperpigmented macules on the trunk, hypertension, hyponatremia, hyperglycemia, and elevated liver enzymes were noted. ACTH-independent CS due to MAS was diagnosed. Although metyrapone (300 mg/m2/day) was started on the 25th day, complete remission could not be achieved despite increasing the dose up to 1,850 mg/m2/day. At 9 months, right total and left three-quarters adrenalectomy was performed. Cortisol decreased substantially, ACTH remained suppressed, rapid tapering of hydrocortisone to physiological dose was not tolerated, and supraphysiological doses were required for 2 months. GNAS analysis from the adrenal tissue showed a pathogenic heterozygous mutation. During 34 months of follow-up, in addition to CS due to MAS, fibrous dysplasia, hypophosphatemic rickets, and peripheral precocious puberty were detected. She is still regularly screened for other endocrinopathies.

Conclusion

Neonatal CS due to MAS is extremely rare. Although there is no specific guideline for diagnosis, treatment, or follow-up, addressing side effects and identifying treatment outcomes will improve quality of life and survival.

Successful ART outcome in a woman with McCune-Albright syndrome: a case report and literature review

McCune-Albright syndrome (MAS) is a rare genetic disease affecting multiple organs, including endocrine tissues. This endocrinopathy is sometimes responsible for infertility, as it may induce an independent functioning of the ovaries leading to anovulatory cycles. This case report describes the infertility journey of a 22-year-old female who had early puberty and irregular periods with high estrogen and progesterone levels, low FSH and LH (on day 3 of her menstrual cycle), and a multi-cystic right ovary. She received several infertility treatments: initially in vitro oocyte maturation (IVM) followed by cyst transvaginal ultrasound-guided aspiration, all unsuccessful. A right hemi-ovariectomy was performed that eventually restored regular cycles and made it possible to perform ovarian stimulation (OS) and in vitro fertilization (IVF). Live birth was obtained after the first embryo transfer.

Iodine and Thyroid Maternal and Fetal Metabolism during Pregnancy

Thyroid hormones and iodine are required to increase basal metabolic rate and to regulate protein synthesis, long bone growth and neuronal maturation. They are also essential for protein, fat and carbohydrate metabolism regulation. Imbalances in thyroid and iodine metabolism can negatively affect these vital functions. Pregnant women are at risk of hypo or hyperthyroidism, in relation to or regardless of their medical history, with potential dramatic outcomes. Fetal development highly relies on thyroid and iodine metabolism and can be compromised if they malfunction. As the interface between the fetus and the mother, the placenta plays a crucial role in thyroid and iodine metabolism during pregnancy. This narrative review aims to provide an update on current knowledge of thyroid and iodine metabolism in normal and pathological pregnancies. After a brief description of general thyroid and iodine metabolism, their main modifications during normal pregnancies and the placental molecular actors are described. We then discuss the most frequent pathologies to illustrate the upmost importance of iodine and thyroid for both the mother and the fetus.

Cushing syndrome as a failed cardiac screen in a patient with McCune–Albright syndrome: a case report

Background

McCune–Albright syndrome is a complex disorder encompassing multiple endocrinopathies. These manifestations are secondary to a mutation in the stimulatory G-protein alpha subunit. Cushing syndrome is due to autonomous secretory function of the adrenal gland and is present in 7.1% of patients with McCune–Albright syndrome. Cardiac newborn screenings assist in the identification of critical congenital heart disease. These screenings have become part of routine postnatal care nationwide.

Case report

A 6-week-old Caucasian male presented to a cardiologist at the University of Tennessee Health Science Center with left ventricular hypertrophy and poor feeding after a failed cardiac newborn screen. He had been previously seen at 2 weeks by a cardiologist on follow-up for abnormal critical congenital heart disease screening. Electrocardiogram and echocardiographic studies identified hypertrophic cardiomyopathy. Other examination findings revealed multiple characteristic café-au-lait lesions along with hypotonia and rounded facies. Given his cardiac disease, he was admitted to the hospital, where an evaluation was done for Cushing syndrome, showing elevated cortisol by immunoassay of 38 μg/dL (1.7–14.0 μg/dL, Vitros 5600) after a dexamethasone suppression test and urinary cortisol elevated to 35 μg/dL/24 hours (reference range 3–9 μg/dL/24 hours) (Esoterix; Calabasas, CA). He was started on metyrapone therapy to block synthesis of cortisol. His cortisol improved and was suppressed less than 2 μg/dL. His hypertension and clinical features of Cushing syndrome improved.

Conclusions

This case demonstrates a unique presentation of Cushing syndrome in a young infant. This is the first case to our knowledge showing significant left ventricular hypertrophy resulting from Cushing syndrome identified following a failure on a critical congenital heart disease screen. It highlights the importance of considering of McCune–Albright syndrome in patients with Cushing syndrome, especially if other clinical features are present. Medical therapy can be used to treat Cushing syndrome and can result in improvement in the cardiovascular pathology.

Coexistence of craniopharyngioma and cranial fibrous dysplasia: a case series of clinicopathological study

Background

Craniopharyngioma (CP) and cranial fibrous dysplasia (CFD) are rare embryonic benign cranial diseases that most commonly present during childhood or adolescence. The coexistence of CP and CFD is extremely rare and has not yet been reported.

Methods

We retrospectively reviewed the data of five patients with concomitant CP and CFD treated at Beijing Tiantan Hospital from January 2003 to January 2021 and summarized their clinicopathological features, treatment modalities, and outcomes. We also performed a comprehensive literature review, tested the patients for characteristic GNAS gene mutations related to CFD, and tested the CP specimens for corresponding Gsα protein to explore the potential connection leading to the coexistence of CP and CFD.

Results

The cohort comprised four men and one woman (median age, 39 years). The symptoms mainly included headache, dizziness, fatigue, polyuria/polydipsia, hypogonadism, and blurred vision. CFD most commonly involved the sphenoid bone (n = 4). Four patients underwent surgery to remove the CP (one trans-sphenoidal and three transcranial resections); complete and subtotal resection were achieved in two patients, respectively. The tumor subtype was adamantinomatous in three patients and unknown in one. The common postoperative complications were panhypopituitarism, diabetes insipidus, and hypothyroidism. The mean follow-up duration was 57.2 months. Two patients required postoperative hormone replacement therapy. Three patients underwent genetic study of the tumor specimens; GNAS mutations were not detected, but these patients were positive for Gsα protein.

Conclusions

Although a definite causative relationship has not been proved, the coexistence of CP and CFD means that potential interplay or an atypical fibrous dysplasia course as uncommon manifestations of CP cannot be excluded. It is more challenging to initiate prompt diagnosis and appropriate treatment for concomitant CP and CFD than for solitary CP because of skull base deformations. Current management strategies are aimed at surgical treating the CP and regularly monitoring the CFD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02281-1.

Treatment of primary infertility in McCune-Albright syndrome: a case report of a successful in vitro fertilization cycle

Objective

To report a case in which pregnancy and live birth were achieved in an infertile patient with McCune-Albright syndrome via in vitro fertilization (IVF).

Design

Case report.

Setting

University hospital.

Patient(s)

A 29-year-old woman with McCune-Albright syndrome who presented with primary infertility due to ovulatory dysfunction and bilateral tubal blockage.

Intervention(s)

In vitro fertilization without unilateral oophorectomy.

Main Outcome Measure(s)

Live birth after IVF treatment.

Result(s)

Fresh IVF stimulation and bilateral oocyte retrieval yielded 12 oocytes and 4 top quality embryos. Fresh single embryo transfer did not result in pregnancy. Live birth occurred after the second frozen embryo transfer cycle.

Conclusion(s)

In vitro fertilization can lead to ongoing pregnancy in infertile patients with McCune-Albright syndrome without requiring unilateral oophorectomy.

Radiographic Diagnosis of Systemic Diseases Manifested in Jaws

Radiographic changes of the oral and maxillofacial hard tissues can be an indication of an underlying systemic disease. In this article, the range of individual disease entities that have both systemic and dental manifestations are reviewed. Images for many conditions are provided to illustrate the radiographic changes. A summary of the most common jaw affected, radiographic and pathognomonic findings, and management aspects is listed in a table format within this article for quick reference.

Fertility in McCune Albright syndrome female: A case study focusing on AMH as a marker of ovarian dysfunction and a literature review

BACKGROUND

The molecular basis of McCune Albright syndrome (MAS) is a recurrent GNAS Postzygotic gain of function sporadic mutation, resulting in a mosaic disease. Most of girls present precocious puberty, caused by the development of recurrent ovarian cysts with autonomous Hyperestrogenic stimulation. After menarche, the majority of patients with ovarian GNAS mutation have menstrual disturbances and infertility.

OBJECTIVES

We wanted to focus on the fertility of MAS females and propose an appropriate management, by a detailed case report and an exhaustive review of the literature on fertility and pregnancy in MAS females.

RESULTS

We present the case of a 29-year-old MAS female, who had previously undergone a unilateral ovariectomy and was managed by in vitro fertilization (IVF). Eight oocytes with many morphological abnormalities were retrieved. The GNAS mutation was found at a low frequency in follicular cells. The ovarian histopathological examination showed developing follicles of all stages, strongly expressing AMH by immunohistochemistry. In addition, AMH was high (45.5 pmol/L) and the AMH / AFC ratio (5.69 pmol/L per follicle) was much higher than in PCOS and control groups (2.16, and 1.34 respectively).

CONCLUSIONS

Ovarian and endometrial involvement can be responsible for infertility in MAS women. IVF and oophorectomy may be useful in management. The genetic characterization of the different tissues may have a prognostic utility. Moreover, we suggest that the AMH could be a marker of the ovarian activity in MAS. Further studies are needed to clarify the potential oocyte abnormalities and the risk of miscarriages in order to guide genetic counseling.

Neonatal cholestasis can be the first symptom of McCune–Albright syndrome: A case report

BACKGROUND

McCune–Albright syndrome (MAS) is caused by postzygotic somatic mutations of the GNAS gene. It is characterized by the clinical triad of fibrous dysplasia, café-au-lait skin spots, and endocrinological dysfunction. Myriad complications in MAS, including hepatobiliary manifestations, are also reported.

CASE SUMMARY

This is a case of a 4-year-old boy who presented with MAS with neonatal cholestasis. He was suspected to have Alagille syndrome due to neonatal cholestasis with intrahepatic bile duct paucity in liver biopsy, peripheral pulmonary artery stenosis, and renal tubular dysfunction. By the age of 2 years, his cholestatic liver injury gradually improved, but he had repeated left femoral fractures. He did not exhibit endocrinological abnormality or café-au-lait skin spots. However, MAS was suspected due to fibrous dysplasia at the age of 4 years. No mutation was identified in the GNAS gene in the DNA isolated from the peripheral blood, but an activating point mutation (c.601C>T, p.Arg201Cys) was observed in the DNA extracted from the affected bone tissue and that extracted from the formalin-fixed paraffin-embedded liver tissue, which was obtained at the age of 1 mo.

CONCLUSION

MAS should be considered as a differential diagnosis for transient cholestasis in infancy.

Heterotrimeric G-protein, Gi1, is involved in the regulation of proliferation, neuronal migration, and dendrite morphology during cortical development in vivo

Heterotrimeric G-proteins are composed of α, β, and γ subunits, and function as signal transducers. Critical roles of the α-subunits of Gi/o family heterotrimeric G-proteins, Gαi2, and Gαo1, have so far been reported in brain development and neurodevelopmental disorders. In this study, we tried to clarify the role of Gαi1, α-subunit of another Gi/o family member Gi1, during corticogenesis, based on the recent identification of its gene abnormalities in neurodevelopmental disorders. In western blot analyses, Gαi1 was found to be expressed in mouse brain in a developmental stage-dependent manner. Morphological analyses revealed that Gαi1 was broadly distributed in cerebral cortex with relatively high expression in the ventricular zone (VZ) at embryonic day (E) 14. Meanwhile, Gαi1 was enriched in membrane area of yet unidentified early mitotic cells in the VZ and the marginal zone at E14. Acute knockdown of Gαi1 with in utero electroporation in cerebral cortex caused cell cycle elongation of the neural progenitor cells and promoted their cell cycle exit. Gαi1-deficient cortical neurons also exhibited delayed radial migration during corticogenesis, with abnormally elongated leading processes and hampered nucleokinesis. In addition, silencing of Gαi1 prevented basal dendrite development. The migration and dendritic phenotypes were at least partially rescued by an RNAi-resistant version of Gαi1. Collectively, these results strongly suggest a crucial role of Gi1 in cortical development, and disturbance of its function may cause deficits in synaptic network formation, leading to neurodevelopmental disorders.

Insights into pituitary tumorigenesis: from Sanger sequencing to next-generation sequencing and beyond

Introduction: This review explores insights provided by next-generation sequencing (NGS) of pituitary tumors and the clinical implications.Areas covered: Although syndromic forms account for just 5% of pituitary tumours, past Sanger sequencing studies pragmatically focused on them. These studies identified mutations in MEN1, CDKN1B, PRKAR1A, GNAS and SDHx causing Multiple Endocrine Neoplasia-1 (MEN1), MEN4, Carney Complex-1, McCune Albright Syndrome and 3P association syndromes, respectively. Furthermore, linkage analysis of single-nucleotide polymorphisms identified AIP mutations in 20% with familial isolated pituitary adenomas (FIPA). NGS has enabled further investigation of sporadic tumours. Thus, mutations of USP8 and CABLES1 were identified in corticotrophinomas, BRAF in papillary craniopharyngiomas and CTNNB1 in adamantinomatous craniopharyngiomas. NGS also revealed that pituitary tumours occur in the DICER1 syndrome, due to DICER1 mutations, and CDH23 mutations occur in FIPA. These discoveries revealed novel therapeutic targets and studies are underway of BRAF inhibitors for papillary craniopharyngiomas, and EGFR and USP8 inhibitors for corticotrophinomas.Expert opinion: It has become apparent that single-nucleotide variants and small insertion/deletion DNA mutations cannot explain all pituitary tumorigenesis. Integrated and improved analyses including whole-genome sequencing, copy number, and structural variation analyses, RNA sequencing and epigenomic analyses, with improved genomic technologies, are likely to further define the genomic landscape.

Peripheral precocious puberty including congenital adrenal hyperplasia: causes, consequences, management and outcomes

Peripheral precocious puberty results from peripheral production of sex steroids independent of activation of the hypothalamic-pituitary gonadal axis. It is much less common than central precocious puberty. Causes are variable and can be congenital or acquired. In this review, we will discuss the diagnosis and management of the most common etiologies including congenital adrenal hyperplasia, McCune Albright syndrome, familial male-limited precocious puberty, and adrenal and gonadal tumors.

Hepatic Lesions Associated With McCune Albright Syndrome

McCune-Albright syndrome (MAS) results from a GNAS gene mutation. It is associated with café au lait macules, fibrous dysplasia, and several endocrinopathies to include gonadotropin-independent precocious puberty, growth hormone excess, Cushing syndrome, thyroid disease, and renal phosphate wasting. It is recognized to be a rare cause of neonatal cholestasis. We describe the hepatic outcome of 3 children with MAS referred to a single national liver unit. All presented with high gamma-glutamyl transpeptidase cholestasis and hepatitis. Cholestasis resolved by 1 year; but hepatic inflammation persisted, and 2 children developed progressive atypical focal nodular hyperplasia and 1 developed hepatoblastoma. This the first reported malignant hepatic lesion associated with MAS. MAS should be considered part of the differential diagnosis of neonatal cholestasis and affected children should be closely monitored for the development of hepatic lesions with regular liver ultrasound and alpha fetoprotein level.

Severe Neonatal Cholestasis as an Early Presentation of McCune-Albright Syndrome

McCune-Albright syndrome (MAS) is a rare genetic disorder characterized by café-au-lait macules, polyostotic fibrous dysplasia and multiple endocrinopathies. Liver involvement, although described, is a rare complication. We review the case of a child with MAS whose initial presentation was characterized by severe neonatal cholestasis. The case demonstrates a severe phenotype of persistent cholestasis in MAS requiring liver transplantation. This phenotype has been previously considered to be a more benign feature. This case highlights the importance of consideration of MAS as an uncommon but important cause of neonatal cholestasis. Early diagnosis may allow for prompt recognition and treatment of other endocrinopathies.

Identification of novel GNAS mutations in intramuscular myxoma using next-generation sequencing with single-molecule tagged molecular inversion probes

Background

Intramuscular myxoma (IM) is a hypocellular benign soft tissue neoplasm characterized by abundant myxoid stroma and occasional hypercellular areas. These tumors can, especially on biopsy material, be difficult to distinguish from low-grade fibromyxoid sarcoma or low-grade myxofibrosarcoma. GNAS mutations are frequently involved in IM, in contrast to these other malignant tumors. Therefore, sensitive molecular techniques for detection of GNAS aberrations in IM, which frequently yield low amounts of DNA due to poor cellularity, will be beneficial for differential diagnosis.

Methods

In our study, a total of 34 IM samples from 33 patients were analyzed for the presence of GNAS mutations, of which 29 samples were analyzed using a gene-specific TaqMan genotyping assay for the detection of GNAS hotspot mutations c.601C > T and c602G > A in IM, and 32 samples using a novel next generation sequencing (NGS)-based approach employing single-molecule tagged molecular inversion probes (smMIP) to identify mutations in exon 8 and 9 of GNAS. Results between the two assays were compared for their ability to detect GNAS mutations with high confidence.

Results

In total, 23 of 34 samples were successfully analyzed with both techniques showing GNAS mutations in 12 out of 23 (52%) samples. The remaining 11 samples were analyzed with either TaqMan assay or smMIP assay only. The TaqMan assay revealed GNAS mutations in 16 out of 29 samples (55%), with six samples c.601C > T (p.R201C; 38%) and ten samples c.602G > A (p.R201H; 62%) missense mutations. The smMIP assay identified mutations in 16 out of 28 samples (57%), with five samples c.601C > T (p.R201C; 31%) and seven samples c.602G > A (p.R201H; 44%) missense mutations. In addition, four samples (25%) revealed novel IM-associated mutations, including c.601C > A (p.R201S), c.602G > T (p.R201L), c.602G > C (p.R201P) and c.680A > G (p.Q227R). Combining the results of both tests, 23 out of 34 sporadic IM samples (68%) showed a GNAS mutation.

Conclusions

Both the TaqMan and the smMIP assay a show a high degree of concordance in detecting GNAS hotspot mutations in IM with comparable sensitivity. However, since the NGS-based smMIP assay permits mutation detection in whole exons of GNAS, a broader range of GNAS mutations can be identified by the smMIP approach.

Neonatal McCune-Albright Syndrome: A Unique Syndromic Profile With an Unfavorable Outcome

Somatic gain‐of‐function mutations of GNAS cause a spectrum of clinical phenotypes, ranging from McCune‐Albright syndrome (MAS) to isolated disease of bone, endocrine glands, and more rarely, other organs. In MAS, a syndrome classically characterized by polyostotic fibrous dysplasia (FD), café‐au‐lait (CAL) skin spots, and precocious puberty, the heterogenity of organ involvement, age of onset, and clinical severity of the disease are thought to reflect the variable size and the random distribution of the mutated cell clone arising from the postzygotic mutation. We report a case of neonatal MAS with hypercortisolism and cholestatic hepatobiliary dysfunction in which bone changes indirectly emanating from the disease genotype, and distinct from FD, led to a fatal outcome. Pulmonary embolism of marrow and bone fragments secondary to rib fractures was the immediate cause of death. Ribs, and all other skeletal segments, were free of changes of typical FD and fractures appeared to be the result of a mild‐to‐moderate degree of osteopenia. The mutated allele was abundant in the adrenal glands and liver, but not in skin, muscle, and fractured ribs, where it could only be demonstrated using a much more sensitive PNA hybridization probe‐based FRET (Förster resonance energy transfer) technique. Histologically, bilateral adrenal hyperplasia and cholestatic disease matched the abundant disease genotype in the adrenals and liver. Based on this case and other sporadic reports, it appears that gain‐of‐function mutations of GNAS underlie a unique syndromic profile in neonates characterized by CAL skin spots, hypercortisolism, hyperthyroidism, hepatic and cardiac dysfunction, and an absence (or latency) of FD, often with a lethal outcome. Taken together, our and previous cases highlight the phenotypic severity and the diagnostic and therapeutic challenges of MAS in neonates. Furthermore, our case specifically points out how secondary bone changes, unrelated to the direct impact of the mutation, may contribute to the unfavorable outcome of very early‐onset MAS. © 2018 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Gαs signaling in skeletal development, homeostasis and diseases

Skeletal development is exquisitely controlled both spatially and temporally by cell signaling networks. Gα_s is the stimulatory α-subunit in a heterotrimeric G protein complex transducing the signaling of G-protein-coupled receptors (GPCRs), responsible for controlling both skeletal development and homeostasis. Gα_s, encoded by the GNAS gene in humans, plays critical roles in skeletal development and homeostasis by regulating commitment, differentiation and maturation of skeletal cells. Gα_s-mediated signaling interacts with the Wnt and Hedgehog signaling pathways, both crucial regulators of skeletal development, remodeling and injury repair. Genetic mutations that disrupt Gα_s functions cause human disorders with severe skeletal defects, such as fibrous dysplasia of bone and heterotopic bone formation. This chapter focuses on the crucial roles of Gα_s signaling during skeletal development and homeostasis, and the pathological mechanisms underlying skeletal diseases caused by GNAS mutations.

Short stature and growth hormone deficiency: unexpected manifestations of McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a rare disease characterised by triad of monostotic or polyostotic fibrous dysplasia, café au-lait skin spots and a variety of endocrine disorders; precocious puberty (PP) being the most common presenting symptom in female patients. Hyperfunction endocrinopathies including hyperthyroidism, growth hormone excess and cortisol excess are typical presentations in MAS. We present a case of 21-year-old woman with clinical and radiological characteristics of MAS triad; she presented with short stature which was attributed to both growth hormone deficiency and PP. Growth hormone deficiency in MAS has not been reported in English medical literature.

Constitutive stimulatory G protein activity in limb mesenchyme impairs bone growth

GNAS mutations leading to constitutively active stimulatory G protein alpha-subunit (Gsα) cause different tumors, fibrous dysplasia of bone, and McCune-Albright syndrome, which are typically not associated with short stature. Enhanced signaling of the parathyroid hormone/parathyroid hormone-related peptide receptor, which couples to multiple G proteins including Gsα, leads to short bones with delayed endochondral ossification. It has remained unknown whether constitutive Gsα activity also impairs bone growth. Here we generated mice expressing a constitutively active Gsα mutant (Gsα-R201H) conditionally upon Cre recombinase (cGsα^R201H mice). Gsα-R201H was expressed in cultured bone marrow stromal cells from cGsα^R201H mice upon adenoviral-Cre transduction. When crossed with mice in which Cre is expressed in a tamoxifen-regulatable fashion (CAGGCre-ER™), tamoxifen injection resulted in mosaic expression of the transgene in double mutant offspring. We then crossed the cGsα^R201H mice with Prx1-Cre mice, in which Cre is expressed in early limb-bud mesenchyme. The double mutant offspring displayed short limbs at birth, with narrow hypertrophic chondrocyte zones in growth plates and delayed formation of secondary ossification center. Consistent with enhanced Gsα signaling, bone marrow stromal cells from these mice demonstrated increased levels of c-fos mRNA. Our findings indicate that constitutive Gsα activity during limb development disrupts endochondral ossification and bone growth. Given that Gsα haploinsufficiency also leads to short bones, as in patients with Albright's hereditary osteodystrophy, these results suggest that a tight control of Gsα activity is essential for normal growth plate physiology.

Treatment of precocious puberty in a McCune–Albright syndrome patient using Chinese medicinal herbs combined with megestrol acetate: A case report

Introduction: McCune–Albright Syndrome (MAS) is a rare congenital sporadic disorder characterized by fibrous bone dysplasia, café-au-lait pigmented spots on the skin, and non-gonadotropin dependent precocious puberty (PP), which is caused by a postzygotic somatic activating mutation in the GNAS gene encoding the alpha subunit of Gs protein. In our case study, we recorded a girl with the onset of MAS and treated her with Chinese medicinal herbs combined with megestrol acetate. We aim to provide a method for the treatment of children with this rare form of precocious puberty.

Case Presention: A 4-year-old girl presented with vaginal bleeding and enlarged breasts. The activating mutation of GNAS was not detected in the patient’s peripheral blood samples, as some had reported. Because of peripheral PP and fibrous dysplasia of the diagnosed bone, the patient was considered as MAS. We chose the Chinese medicinal herbs combined with megestrol acetate for treatment, and the patient was effectively treated.

Conclusion: The combination therapy of Chinese medicinal herbs plus megestrol acetate in managing PP in an MAS is one of the useful treatments.

Expression of an active Gαs mutant in skeletal stem cells is sufficient and necessary for fibrous dysplasia initiation and maintenance

Fibrous dysplasia (FD) is a disease caused by postzygotic activating mutations of GNAS (R201C and R201H) that encode the α-subunit of the Gs stimulatory protein. FD is characterized by the development of areas of abnormal fibroosseous tissue in the bones, resulting in skeletal deformities, fractures, and pain. Despite the well-defined genetic alterations underlying FD, whether GNAS activation is sufficient for FD initiation and the molecular and cellular consequences of GNAS mutations remains largely unresolved, and there are no currently available targeted therapeutic options for FD. Here, we have developed a conditional tetracycline (Tet)-inducible animal model expressing the GαsR201C in the skeletal stem cell (SSC) lineage (Tet-GαsR201C/Prrx1-Cre/LSL-rtTA-IRES-GFP mice), which develops typical FD bone lesions in both embryos and adult mice in less than 2 weeks following doxycycline (Dox) administration. Conditional GαsR201C expression promoted PKA activation and proliferation of SSCs along the osteogenic lineage but halted their differentiation to mature osteoblasts. Rather, as is seen clinically, areas of woven bone admixed with fibrous tissue were formed. GαsR201C caused the concomitant expression of receptor activator of nuclear factor kappa-B ligand (Rankl) that led to marked osteoclastogenesis and bone resorption. GαsR201C expression ablation by Dox withdrawal resulted in FD-like lesion regression, supporting the rationale for Gαs-targeted drugs to attempt FD cure. This model, which develops FD-like lesions that can form rapidly and revert on cessation of mutant Gαs expression, provides an opportunity to identify the molecular mechanism underlying FD initiation and progression and accelerate the development of new treatment options.

Induced GnasR201H expression from the endogenous Gnas locus causes fibrous dysplasia by up-regulating Wnt/β-catenin signaling

Fibrous dysplasia (FD; Online Mendelian Inheritance in Man no. 174800) is a crippling skeletal disease caused by activating mutations of the GNAS gene, which encodes the stimulatory G protein Gα_s FD can lead to severe adverse conditions such as bone deformity, fracture, and severe pain, leading to functional impairment and wheelchair confinement. So far there is no cure, as the underlying molecular and cellular mechanisms remain largely unknown and the lack of appropriate animal models has severely hampered FD research. Here we have investigated the cellular and molecular mechanisms underlying FD and tested its potential treatment by establishing a mouse model in which the human FD mutation (R201H) has been conditionally knocked into the corresponding mouse Gnas locus. We found that the germ-line FD mutant was embryonic lethal, and Cre-induced Gnas FD mutant expression in early osteochondral progenitors, osteoblast cells, or bone marrow stromal cells (BMSCs) recapitulated FD features. In addition, mosaic expression of FD mutant Gα_s in BMSCs induced bone marrow fibrosis both cell autonomously and non-cell autonomously. Furthermore, Wnt/β-catenin signaling was up-regulated in FD mutant mouse bone and BMSCs undergoing osteogenic differentiation, as we have found in FD human tissue previously. Reduction of Wnt/β-catenin signaling by removing one Lrp6 copy in an FD mutant line significantly rescued the phenotypes. We demonstrate that induced expression of the FD Gα_s mutant from the mouse endogenous Gnas locus exhibits human FD phenotypes in vivo, and that inhibitors of Wnt/β-catenin signaling may be repurposed for treating FD and other bone diseases caused by Gα_s activation.

Evaluation and Treatment Results of Ovarian Cysts in Childhood and Adolescence: A Multicenter, Retrospective Study of 100 Patients

STUDY OBJECTIVE

To investigate the characteristics of children with ovarian cysts and evaluate treatment strategies.

DESIGN

Retrospective study.

SETTING

Eight pediatric endocrinology clinics, Turkey.

PARTICIPANTS

A total of 100 children and adolescents with ovarian cysts.

INTERVENTIONS

Patient data collected via retrospective chart review. Patients were stratified according to age into 4 groups (newborns, 1-12 months, 1-8 years, and 8-18 years).

MAIN OUTCOME MEASURES

Special emphasis was given to torsion and tumor cases, concomitant diseases, treatment modalities, and problems during follow-up.

RESULTS

Most newborns and infants were asymptomatic with the cysts being discovered incidentally; in girls ages 1-8, symptoms were common, including breast budding (47.1%, 16 of 34) and vaginal bleeding (29.4%, 10 of 34). Girls older than 8 years mostly presented with abdominal pain (31.6%, 12 of 38) and menstrual irregularity (21.1%, 8 of 38). Most of our patients were diagnosed with a simple ovarian cyst, but 9 patients were found to have ovarian tumors. Ovarian torsion was detected in 7 patients; 5 with large and 2 with small cysts (<20 mm). Two patients had central precocious puberty (CPP) at presentation and 5 patients developed CPP during follow-up. The surgical intervention rate was high (38%, 38 of 100), but was associated with earlier treatment year, and this association remained significant after adjusting for confounders (P = .035).

CONCLUSION

Most girls have simple cysts, which have a favorable prognosis without intervention; however, there might be coexisting pathologies or complications such as tumors, torsion, and CPP; hence these patients should be evaluated accordingly and treated with a multidisciplinary approach.

Heterotrimeric G Stimulatory Protein α Subunit Is Required for Intestinal Smooth Muscle Contraction in Mice

BACKGROUND & AIMS

The α subunit of the heterotrimeric G stimulatory protein (Gsa), encoded by the guanine nucleotide binding protein, α-stimulating gene (Gnas, in mice), is expressed ubiquitously and mediates receptor-stimulated production of cyclic adenosine monophosphate and activation of the protein kinase A signaling pathway. We investigated the roles of Gsa in vivo in smooth muscle cells of mice.

METHODS

We performed studies of mice with Cre recombinase-mediated disruption of Gnas in smooth muscle cells (GsaSMKO and SM22-CreERT2, induced in adult mice by tamoxifen). Intestinal tissues were collected for histologic, biochemical, molecular, cell biology, and physiology analyses. Intestinal function was assessed in mice using the whole-gut transit time test. We compared gene expression patterns of intestinal smooth muscle from mice with vs without disruption of Gnas. Biopsy specimens from ileum of patients with chronic intestinal pseudo-obstruction and age-matched control biopsies were analyzed by immunohistochemistry.

RESULTS

Disruption of Gnas in smooth muscle of mice reduced intestinal motility and led to death within 4 weeks. Tamoxifen-induced disruption of Gnas in adult mice impaired contraction of intestinal smooth muscle and peristalsis. More than 80% of these died within 3 months of tamoxifen exposure, with features of intestinal pseudo-obstruction characterized by chronic intestinal dilation and dysmotility. Gsa deficiency reduced intestinal levels of cyclic adenosine monophosphate and transcriptional activity of the cyclic adenosine monophosphate response element binding protein 1 (CREB1); this resulted in decreased expression of the forkhead box F1 gene (Foxf1) and protein, and contractile proteins, such as myosin heavy chain 11; actin, α2, smooth muscle, aorta; calponin 1; and myosin light chain kinase. We found decreased levels of Gsa, FOXF1, CREB1, and phosphorylated CREB1 proteins in intestinal muscle layers of patients with chronic intestinal pseudo-obstruction, compared with tissues from controls.

CONCLUSIONS

Gsa is required for intestinal smooth muscle contraction in mice, and its levels are reduced in ileum biopsies of patients with chronic intestinal pseudo-obstruction. Mice with disruption of Gnas might be used to study human chronic intestinal pseudo-obstruction.

Fetal neonatal hyperthyroidism: diagnostic and therapeutic approachment

Fetal and neonatal hyperthyroidism may occur in mothers with Graves' disease. Fetal thyrotoxicosis manifestation is observed with the transition of TSH receptor stimulating antibodies to the fetus from the 17th-20th weeks of pregnancy and with the fetal TSH receptors becoming responsive after 20 weeks. The diagnosis is confirmed by fetal tachycardia, goiter and bone age advancement in pregnancy and maternal treatment is conducted in accordance. The probability of neonatal hyperthyroidism is high in the babies of mothers that have ongoing antithyroid requirement and higher antibody levels in the last months of pregnancy. Clinical manifestation may be delayed by 7-17 days because of the antithyroid drugs taken by the mother. Neonatal hyperthyroidism symptoms can be confused with sepsis and congenital viral infections. Herein, the diagnosis and therapeutic approach are reviewed in cases of fetal neonatal hyperthyroidism.

Hypothyroidism in McCune-Albright Syndrome and Role of Bone Scan in Management of Fibrous Dysplasia: An Unusual Case Scenario with Review of Literature

The McCune–Albright syndrome (MAS) is a triad of café-au-lait skin pigmentation, precocious puberty (PP), and polyostotic fibrous dysplasia of bone (FD). In general, FD seems to be the most common component of MAS but very rarely precocious puberty can be found in association with café-au-lait skin pigmentation in the absence of FD (about 1% of the cases). Therefore, a more clinically relevant definition of MAS is fibrous dysplasia of bone (FD) and at least one of the typical hyperfunctioning endocrinopathy and/or café-au-lait spots, with almost any combination possible. Bone scan can be the modality of choice to look for bone disease burden of fibrous dysplasia in most patients of MAS and may change the management accordingly. Most of the cases of MAS reported worldwide are associated with hyperthyroidism, up to best of our knowledge on the basis of literature search in pubmed and Google; no case was reported with hypothyroidism. Herein, we report a 12-year-old girl diagnosed with MAS and associated hypothyroidism. We have also reviewed the MAS related literature.

Role of a heterotrimeric G-protein, Gi2, in the corticogenesis: possible involvement in periventricular nodular heterotopia and intellectual disability

We analyzed the role of a heterotrimeric G-protein, Gi2, in the development of the cerebral cortex. Acute knockdown of the α-subunit (Gαi2) with in utero electroporation caused delayed radial migration of excitatory neurons during corticogenesis, perhaps because of impaired morphology. The migration phenotype was rescued by an RNAi-resistant version of Gαi2. On the other hand, silencing of Gαi2 did not affect axon elongation, dendritic arbor formation or neurogenesis at ventricular zone in vivo. When behavior analyses were conducted with acute Gαi2-knockdown mice, they showed defects in social interaction, novelty recognition and active avoidance learning as well as increased anxiety. Subsequently, using whole-exome sequencing analysis, we identified a de novo heterozygous missense mutation (c.680C>T; p.Ala227Val) in the GNAI2 gene encoding Gαi2 in an individual with periventricular nodular heterotopia and intellectual disability. Collectively, the phenotypes in the knockdown experiments suggest a role of Gαi2 in the brain development, and impairment of its function might cause defects in neuronal functions which lead to neurodevelopmental disorders.

Expression profiles of the Gα subunits during Xenopus tropicalis embryonic development

Heterotrimeric G protein signaling plays major roles during different cellular events. However, there is a limited understanding of the molecular mechanisms underlying G protein control during embryogenesis. G proteins are highly conserved and can be grouped into four subfamilies according to sequence homology and function. To further studies on G protein function during embryogenesis, the present analysis identified four Gα subunits representative of the different subfamilies and determined their spatiotemporal expression patterns during Xenopus tropicalis embryogenesis. Each of the Gα subunit transcripts was maternally and zygotically expressed, and, as development progressed, dynamic expression patterns were observed. In the early developmental stages, the Gα subunits were expressed in the animal hemisphere and dorsal marginal zone. While expression was observed at the somite boundaries, in vascular structures, in the eye, and in the otic vesicle during the later stages, expression was mainly found in neural tissues, such as the neural tube and, especially, in the cephalic vesicles, neural crest region, and neural crest-derived structures. Together, these results support the pleiotropism and complexity of G protein subfamily functions in different cellular events. The present study constitutes the most comprehensive description to date of the spatiotemporal expression patterns of Gα subunits during vertebrate development.

Neonatal McCune-Albright syndrome with survival beyond two years

McCune-Albright syndrome (MAS) is a rare disease resulting from a somatic, mosaic mutation of GNAS1 encoding the G_s α subunit of the G-protein coupled membrane receptor responsible for multiple hormonal signaling cascades. We present a patient with neonatal MAS who initially presented with neonatal diabetes and concern for congenital cardiac disease, and subsequently was found to have significant ACTH-independent neonatal Cushing syndrome. Her course included multi-system organ involvement, although she initially did not have obvious findings consistent with the MAS classic triad of café-au-lait macules, fibrous dysplasia, or peripheral precocious puberty. After medical and surgical treatment, she remains the only reported survivor of neonatal MAS. This clinical report alerts clinicians to the possibility of this disease in neonates with non-classical endocrine and non-endocrine manifestations of MAS, and demonstrates that this very early presentation is potentially survivable. © 2016 Wiley Periodicals, Inc.

Management of hyperthyroidism in children

Treatment of hyperthyroidism in children differs according to its etiology; in particular, the optimal therapy of Graves' disease (GD) remains a matter of debate and there is currently no evidence-based therapeutic strategy that is universally adopted in all the countries. Areas covered: The most recent treatment strategies in the different pediatric conditions which may be associated with hyperthyroidism. We searched PubMed and Cochrane (1990 to 2016) in order to identify articles to include in this review using the following terms: Hyperthyroidism, Childhood, Antithyroid drug therapy, Thyroidectomy, Radioactive iodine. Expert commentary: Although pharmacological therapy represents the first-line approach for GD children, we recommend to individualize, as much as possible, the overall therapeutic approach, with no prejudices towards radical therapies, particularly in the cases with frequent relapses. Clinical and laboratory preferential criteria for an individualized therapeutic approach to GD children are given. Treatment procedures for hyperthyroid children without GD are also discussed.

Onyx embolization of an intraosseous pseudoaneurysm of the middle meningeal artery in a patient with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome

A 13-year-old boy with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome presented with an enlarging "lump" on his right forehead. A head CT scan revealed a polyostotic fibrous dysplasia involving the entire skull. A 3.4-cm right frontal osseous cavity and an overlying right forehead subcutaneous soft-tissue mass were seen, measuring 5.2 cm in diameter and 1.6 cm thick. Ultrasound of the cavity and overlying mass showed swirling of blood and an arterialized waveform. MRI revealed an en plaque meningioma underlying the cavity. An intraosseous pseudoaneurysm fed by 3 distal anterior division branches of the right middle meningeal artery (MMA) with contrast extravasation was found on angiography. Two MMA feeders were embolized with Onyx, with anterograde filling of the intraosseous cavity with Onyx. A small pocket of residual intracavity contrast filling postembolization from a smaller third MMA feeder eventually thrombosed and the forehead lump regressed.

G-Protein α-Subunit Gsα Is Required for Craniofacial Morphogenesis

The heterotrimeric G protein subunit Gsα couples receptors to activate adenylyl cyclase and is required for the intracellular cAMP response and protein kinase A (PKA) activation. Gsα is ubiquitously expressed in many cell types; however, the role of Gsα in neural crest cells (NCCs) remains unclear. Here we report that NCCs-specific Gsα knockout mice die within hours after birth and exhibit dramatic craniofacial malformations, including hypoplastic maxilla and mandible, cleft palate and craniofacial skeleton defects. Histological and anatomical analysis reveal that the cleft palate in Gsα knockout mice is a secondary defect resulting from craniofacial skeleton deficiencies. In Gsα knockout mice, the morphologies of NCCs-derived cranial nerves are normal, but the development of dorsal root and sympathetic ganglia are impaired. Furthermore, loss of Gsα in NCCs does not affect cranial NCCs migration or cell proliferation, but significantly accelerate osteochondrogenic differentiation. Taken together, our study suggests that Gsα is required for neural crest cells-derived craniofacial development.

[Recovery of Cushing syndrome revealing McCune-Albright syndrome]

Cushing syndrome (CS) is a rare feature of McCune-Albright syndrome. Treatments consist of bilateral adrenalectomy followed by lifelong glucocorticoid and mineralocorticoid treatment. However, cases of spontaneous remission of CS have been reported in the literature. We report a case of McCune-Albright syndrome with CS treated with metyrapone for 30 months with prolonged remission after a 12-year follow-up. Adrenalectomy may be avoided in some cases of CS caused by McCune-Albright syndrome. Metyrapone could be a good alternative to surgical treatment.

Neonatal McCune-Albright syndrome with systemic involvement: a case report

INTRODUCTION

McCune-Albright syndrome is a rare sporadic disease characterized by fibrous bone dysplasia, café-au-lait skin spots and variable hyperfunctional endocrinopathies. McCune-Albright syndrome is caused by somatic postzygotic activating mutations in the GNAS gene that produce a broad spectrum of effects.

CASE PRESENTATION

We report a case of McCune-Albright syndrome with multi-organ manifestations in the neonatal period. A newborn preterm black girl was referred to our Neonatal Intensive Care Unit at the age of 17 days for suspected extrahepatic cholestasis. On clinical examination she presented failure to thrive, jaundice, hypertension, marked hypotonia and café-au-lait spots on her back and lower limbs. An abdominal ultrasound excluded extrahepatic causes of cholestasis but revealed bilateral serpiginous adrenal hyperplasia. These clinical findings suggested a diagnosis of McCune-Albright syndrome with multi-organ involvement. Laboratory data confirmed adrenocorticotropic hormone-independent Cushing's syndrome, hyperthyroidism, cholestasis and elevated transaminases. Ventricular hypertrophy was demonstrated by echocardiography. The baby girl underwent medical treatment of Cushing's syndrome with metyrapone which was followed by a rapid recovery. A mosaic activating GNAS gene mutation was found on DNA extracted from a buccal swab sample. However, she died at 4 months due to a respiratory infection.

CONCLUSION

In the neonatal period the diagnosis of McCune-Albright syndrome depends on having a high index of suspicion and café-au-lait spots may be the clue for the diagnosis.

McCune Albright syndrome in association with excessive GH secretion: case report

McCune-Albright Syndrome is a rare syndrome characterized with excessive function of peripheral endocrine organs and activating mutations of the stimulatory G protein alpha subunit are involved in the pathogenesis. The three main findings of the disease include hyperpigmented café au lait spots, fibrous dysplasia and increased endocrine functions and excessive secretion of growth hormone is observed in 21% of the patients. Clinical signs may be missed in these patients because of precocious puberty and craniofacial fibrous dysplasia. Since radiotherapy causes to sarcomatous changes and transsphenoidal surgery may cause to severe thickening in the cranial bones, they are not appropriate treatment options and medical treatment is recommended. Bromocriptine, cabergoline and octreotide or different combinations of these drugs are used in treatment and pegvisomant has also been used in recent years. Here, we present a male patient aged 12 years and 7 months to show gigantism as a rare clinical reflection of McCune-Albright Syndrome with an excessive height (197 cm), café au lait spots, growht hormone levels which could not be supressed with oral glucose tolerance test and increased prolactin levels.

Constitutive expression of Gsα(R201C) in mice produces a heritable, direct replica of human fibrous dysplasia bone pathology and demonstrates its natural history

Fibrous dysplasia of bone (FD) is a crippling skeletal disease associated with postzygotic mutations (R201C, R201H) of the gene encoding the α subunit of the stimulatory G protein, Gs. By causing a characteristic structural subversion of bone and bone marrow, the disease results in deformity, hypomineralization, and fracture of the affected bones, with severe morbidity arising in childhood or adolescence. Lack of inheritance of the disease in humans is thought to reflect embryonic lethality of germline-transmitted activating Gsα mutations, which would only survive through somatic mosaicism. We have generated multiple lines of mice that express Gsα(R201C) constitutively and develop an inherited, histopathologically exact replica of human FD. Robust transgene expression in neonatal and embryonic tissues and embryonic stem (ES) cells were associated with normal development of skeletal tissues and differentiation of skeletal cells. As in humans, FD lesions in mice developed only in the postnatal life; a defined spatial and temporal pattern characterized the onset and progression of lesions across the skeleton. In individual bones, lesions developed through a sequence of three distinct histopathological stages: a primary modeling phase defined by endosteal/medullary excess bone formation and normal resorption; a secondary phase, with excess, inappropriate remodeling; and a tertiary fibrous dysplastic phase, which reproduced a full-blown replica of the human bone pathology in mice of age ≥1 year. Gsα mutations are sufficient to cause FD, and are per se compatible with germline transmission and normal embryonic development in mice. Our novel murine lines constitute the first model of FD.

Acromegaly and McCune-Albright syndrome

BACKGROUND

McCune-Albright syndrome (MAS) includes the triad of poly/monostotic fibrous dysplasia, café-au-lait spots, and hyperfunctioning endocrinopathies. Acromegaly affects around 20% of MAS patients.

AIMS

The objective was to review all reported cases of acromegaly associated with MAS.

METHODS

All studies and case reports of acromegaly in patients with MAS were systematically sought in the world literature up to January 2013. We also included new data (from three unreported cases) and updated data on 23 previously reported patients from our two centers.

RESULTS

We reviewed the cases of 112 patients (65 males). Mean age at diagnosis of acromegaly was 24.4 years (range, 3-64). Among the 40 pediatric patients, 23 (57%) had precocious puberty. GH/IGF-1 excess was suggested by accelerated growth in 85% of pediatric cases. Acromegaly was almost always associated with skull base fibrous dysplasia. Modern imaging techniques (computed tomography or magnetic resonance imaging) revealed an adenoma in 54% of the patients (macroadenoma in more than two-thirds). Median GH levels and mean IGF-1 SD score at diagnosis were 57 μg/L (2.8 to 291 μg/L) and 8 (2.3 to 24), respectively. Hyperprolactinemia was present in 81% (mean, 149 μg/L; range, 21-600). Pituitary surgery, performed in 25 cases, very rarely cured the GH/IGF-1 excess. Somatostatin analogs improved GH/IGF-1 levels in most patients but achieved control of acromegaly in only 17 (30%) of 56 patients. Pegvisomant achieved normal IGF-1 levels in 10 of 13 cases.

CONCLUSION

Acromegaly, which is present in 20-30% of patients with MAS, raises particular diagnostic and therapeutic issues.

Dental perspectives in fibrous dysplasia and McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a rare multisystem disorder characterized by the triad of polyostotic fibrous dysplasia (FD), endocrine disorders, and café-au-lait skin pigmentation. Ninety percent of MAS patients have FD lesions in the craniofacial area, resulting in significant orofacial deformity, dental disorders, bone pain, and compromised oral health. Maxillomandibular FD is also associated with dental developmental disorders, malocclusion, and high caries index. There are limited data on the outcomes of dental treatments in maxillomandibular FD/MAS patients, because clinicians and researchers have limited access to patients, and there are concerns that dental surgery may activate quiescent jaw FD lesions to grow aggressively. This report highlights current perspectives on dental management issues associated with maxillomandibular FD within the context of MAS.

Spinal polyostotic fibrous dysplasia in two adults: Does only biopsy unravel the mystery?

Polyostotic fibrous dysplasia is a rare non-inheritable genetic disease due to mutation in GNAS gene. Here we present two adults who were accidentally detected lytic lesions in spine and after extensive evaluation for malignancies; was diagnosed on biopsy. Current concept of the disease and management is discussed.

Analysis of GNAS1 mutations in myxoid soft tissue and bone tumors

The aim of this study was to characterize the prevalence of GNAS1 mutations in various tumor types, including intramuscular myxomas, fibrous dysplasias, and other myxoid tumors and implications for malignant transformation. PCR and direct sequencing were applied to analyze GNAS1 mutation status using genomic DNA isolated from 97 formalin-fixed and paraffin-embedded samples, including 63 intramuscular myxomas, 19 various myxoid lesions, 8 cases of sporadically occurring fibrous dysplasia, and 7 cases of atrial myxoma. Mutations of GNAS1 were detected in 23 out of 63 (36.5%) intramuscular myxoma patients, with mutational hotspots R201H and R201C being equally affected. GNAS1 mutations in codon 201 were found in 5 out of 8 fibrous dysplasias (62.5%), while no mutations of GNAS1 were detected in the other studied entities, including atrial myxomas. GNAS1 mutation analysis has diagnostic value in screening patients with intramuscular myxoma and patients with fibrous dysplasia.

Diagnostic value of investigating GNAS mutations in fibro-osseous lesions: a retrospective study of 91 cases of fibrous dysplasia and 40 other fibro-osseous lesions

GNAS (guanine nucleotide-binding protein/α-subunit) mutations that induce the activation of G-protein α-subunit participate in the pathogenesis of fibrous dysplasia. The aim of this study was to evaluate the sensitivity and specificity of GNAS mutations in fibrous dysplasia and other fibro-osseous lesions, to assess the value of investigating this mutation in the diagnosis of fibro-osseous lesions. We studied 91 cases of fibrous dysplasia. The quality and/or quantity of genomic DNA were suitable for molecular analysis for 51 cases of fibrous dysplasia. GNAS mutations were investigated by three techniques: high-resolution melting (exon 8), allele-specific PCR (exons 8 and 9) and/or direct DNA sequencing (exons 8 and 9). Fibrous dysplasia samples were classified blind to the GNAS mutation status into six histological subtypes as conventional, fibro-involutive, osteosclerosing, cementifying, osteocartilaginous and with prominent aneurysmal cystic changes. We also studied 14 cases of low-grade osteosarcoma, 21 cases of ossifying fibroma, 3 cases of osteofibrous dysplasia, 1 case of osseous dysplasia of the jawbone and 1 post-traumatic lesion of the ribs. Twenty-three cases of fibrous dysplasia (45%) showed mutations of codon 201 (exon 8, p.R201H or p.R201C). No mutation was found on codon 227 (exon 9). GNAS mutations in conventional fibrous dysplasia were detected in the same proportion (47%) as in the other histological subtypes (47%, P=0.96), regardless of sex (P=0.44), age (P=0.90) and location (P=1). GNAS mutations were not detected in any other fibro-osseous lesions. The GNAS mutation was thus specific to fibrous dysplasia in the context of fibro-osseous lesions. The particular mosaicism of mutant and non-mutant cells within the lesion or the existence of other mutations not already described could explain the lack of GNAS mutation in cases of fibrous dysplasia. Investigating this mutation may constitute a valuable complementary diagnostic tool, despite its low sensitivity, particularly in unconventional morphologically different subtypes of fibrous dysplasia.

Hepatocellular benign tumors-from molecular classification to personalized clinical care

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors that develop most frequently in women without cirrhosis. Genomic approaches have identified signaling pathways related to these benign hepatocyte proliferations. FNH, a polyclonal lesion, is characterized by local vascular abnormalities and heterogeneous activation of Wnt/β-catenin and transforming growth factor β signaling. Four major subgroups of HCAs have been identified based on mutations in specific oncogenes and tumor suppressor genes. Each molecular subtype of HCA has been associated with specific pathways, providing new information about benign tumorigenesis. Key features include metabolic alterations (induced by defects in HNF1A), oncogene-induced inflammation (activation of JAK-STAT signaling in inflammatory adenomas), and an association between activation of Wnt/β-catenin signaling and progression of HCAs in hepatocellular carcinomas. Benign hepatocellular tumors can be classified using immunohistochemical analyses. Studies of genotypes and phenotypes of FNH and HCAs have led to the identification of risk factors and improved invasive and noninvasive diagnostic techniques, evaluation of prognosis, and treatment. We review the molecular pathways involved in benign hepatocyte proliferation and discuss how this basic knowledge has been progressively translated into personalized clinical care.